1. Field of the Invention
The present invention relates to a centrifugal clutch and a straddle type vehicle including the centrifugal clutch.
2. Description of Related Art
A centrifugal clutch in which outer plates and inner plates are press-fitted together with the use of roller weights moved by centrifugal force is conventionally used in straddle type vehicles such as motorcycles and four-wheeled buggies (for example, see JP-A-2007-38736).
This type of centrifugal clutch includes a clutch housing rotating with an input shaft and a clutch boss disposed inside the clutch housing. Outer plates are mounted on the clutch housing. Inner plates facing the outer plates are mounted on the clutch boss. Roller weights are mounted between the clutch housing and the outer plates. Cam surfaces for guiding the roller weights are formed on the clutch housing. When the roller weights receive centrifugal force and move outward in a radial direction of the input shaft, they are guided by the cam surfaces in directions such that the outer plates and the inner plates are press-fitted together.
The vehicle width of a straddle type vehicle is preferably not excessively large since a rider has difficulty in straddling the vehicle. However, when an engine with a large displacement is used, the entire engine unit becomes large since a large-sized centrifugal clutch has to be used. Therefore, there is a problem that the vehicle width becomes accordingly large.